Examkin

Soru

Zorluk: Çok zorInterpreting Laboratory Results

A physician is evaluating five patients who present with complex acid-base and electrolyte abnormalities. Match each patient's clinical and laboratory profile to the most likely underlying diagnosis. All serum electrolytes are reported in mEq/L. The reference range for serum anion gap is 8−128-12 mEq/L.

  • Patient A: pH 7.257.25, PaCO 2_2 3030 mmHg, Na +^+ 140140 mEq/L, K +^+ 2.12.1 mEq/L, Cl −^- 115115 mEq/L, HCO 3−_3^- 1313 mEq/L, Urine pH 6.86.8, Urine AG positive, BP 120/80120/80 mmHgDistal (Type 11) renal tubular acidosis
  • Patient B: pH 7.307.30, PaCO 2_2 3636 mmHg, Na +^+ 139139 mEq/L, K +^+ 5.85.8 mEq/L, Cl −^- 110110 mEq/L, HCO 3−_3^- 1717 mEq/L, Urine pH 5.25.2, Urine AG positive, BP 130/85130/85 mmHgHyporeninemic hypoaldosteronism (Type 44 RTA)
  • Patient C: pH 7.527.52, PaCO 2_2 4848 mmHg, Na +^+ 136136 mEq/L, K +^+ 2.62.6 mEq/L, Cl −^- 8686 mEq/L, HCO 3−_3^- 3838 mEq/L, Urine Cl −^- 88 mEq/L, BP 115/75115/75 mmHgSurreptitious vomiting
  • Patient D: pH 7.507.50, PaCO 2_2 4646 mmHg, Na +^+ 139139 mEq/L, K +^+ 2.52.5 mEq/L, Cl −^- 9292 mEq/L, HCO 3−_3^- 3535 mEq/L, Urine Cl −^- 6868 mEq/L, BP 110/70110/70 mmHgSurreptitious loop diuretic abuse
  • Patient E: pH 7.517.51, PaCO 2_2 4747 mmHg, Na +^+ 142142 mEq/L, K +^+ 2.72.7 mEq/L, Cl −^- 9494 mEq/L, HCO 3−_3^- 3636 mEq/L, Urine Cl −^- 5555 mEq/L, BP 175/105175/105 mmHgPrimary hyperaldosteronism

Cevap

Patient A matches with Distal (Type 1) RTA, Patient B with Hyporeninemic hypoaldosteronism, Patient C with Surreptitious vomiting, Patient D with Surreptitious loop diuretic abuse, and Patient E with Primary hyperaldosteronism.
Each patient requires a systemic approach to acid-base interpretation. Matching correctly relies on integrating multiple parameters: differentiating RTA types by potassium and urine pH, and evaluating metabolic alkalosis using urine chloride and blood pressure.

Adım Adım Çözüm

1
Calculate the serum anion gap for acidotic patients
Patients A and B have a normal serum anion gap (1212 mEq/L), confirming hyperchloremic metabolic acidosis.
To classify the metabolic acidosis and determine if it is due to unmeasured anions or bicarbonate loss.
2
Evaluate potassium, urine anion gap, and urine pH in normal anion gap acidosis
Patient A has hypokalemia and urine pH >5.5> 5.5, indicating Type 11 RTA. Patient B has hyperkalemia and urine pH <5.5< 5.5, indicating Type 44 RTA.
To differentiate between renal tubular acidosis subtypes.
3
Analyze urine chloride in patients with metabolic alkalosis
Patient C has low urine Cl −^- (<20< 20 mEq/L), indicating saline-responsive alkalosis. Patients D and E have high urine Cl −^- (>20> 20 mEq/L), indicating saline-resistant alkalosis.
To determine volume status and chloride responsiveness.
4
Assess blood pressure in saline-resistant metabolic alkalosis
Patient D is normotensive, pointing to diuretic abuse. Patient E is hypertensive, pointing to primary hyperaldosteronism.
To distinguish between mineralocorticoid excess and renal salt-wasting states.

Anahtar Kavram

Interpretation of complex acid-base disorders requires algorithmic evaluation of the serum anion gap, potassium, urine pH, urine anion gap, urine chloride, and blood pressure to isolate the precise pathophysiological mechanism.
Bu soruyu puanla

Konular

Interpreting Laboratory Results

Bu konudan daha fazla soru